2 net_socket.c -- Handle various kinds of sockets.
3 Copyright (C) 1998-2005 Ivo Timmermans,
4 2000-2012 Guus Sliepen <guus@tinc-vpn.org>
5 2006 Scott Lamb <slamb@slamb.org>
6 2009 Florian Forster <octo@verplant.org>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27 #include "connection.h"
39 /* Needed on Mac OS/X */
41 #define SOL_TCP IPPROTO_TCP
44 int addressfamily = AF_UNSPEC;
46 int seconds_till_retry = 5;
50 listen_socket_t listen_socket[MAXSOCKETS];
52 list_t *outgoing_list = NULL;
56 static void configure_tcp(connection_t *c) {
60 int flags = fcntl(c->socket, F_GETFL);
62 if(fcntl(c->socket, F_SETFL, flags | O_NONBLOCK) < 0) {
63 logger(LOG_ERR, "fcntl for %s: %s", c->hostname, strerror(errno));
66 unsigned long arg = 1;
68 if(ioctlsocket(c->socket, FIONBIO, &arg) != 0) {
69 logger(LOG_ERR, "ioctlsocket for %s: %d", c->hostname, sockstrerror(sockerrno));
73 #if defined(SOL_TCP) && defined(TCP_NODELAY)
75 setsockopt(c->socket, SOL_TCP, TCP_NODELAY, (void *)&option, sizeof(option));
78 #if defined(SOL_IP) && defined(IP_TOS) && defined(IPTOS_LOWDELAY)
79 option = IPTOS_LOWDELAY;
80 setsockopt(c->socket, SOL_IP, IP_TOS, (void *)&option, sizeof(option));
84 static bool bind_to_interface(int sd) {
87 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
90 #endif /* defined(SOL_SOCKET) && defined(SO_BINDTODEVICE) */
92 if(!get_config_string (lookup_config (config_tree, "BindToInterface"), &iface))
95 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
96 memset(&ifr, 0, sizeof(ifr));
97 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
98 ifr.ifr_ifrn.ifrn_name[IFNAMSIZ - 1] = 0;
100 status = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
102 logger(LOG_ERR, "Can't bind to interface %s: %s", iface,
106 #else /* if !defined(SOL_SOCKET) || !defined(SO_BINDTODEVICE) */
107 logger(LOG_WARNING, "%s not supported on this platform", "BindToInterface");
113 static bool bind_to_address(connection_t *c) {
115 struct addrinfo *ai_list;
116 struct addrinfo *ai_ptr;
117 struct addrinfo ai_hints;
121 assert(c->socket >= 0);
124 if(!get_config_string(lookup_config(config_tree, "BindToAddress"),
128 assert(node != NULL);
130 memset(&ai_hints, 0, sizeof(ai_hints));
131 ai_hints.ai_family = c->address.sa.sa_family;
132 /* We're called from `do_outgoing_connection' only. */
133 ai_hints.ai_socktype = SOCK_STREAM;
134 ai_hints.ai_protocol = IPPROTO_TCP;
138 status = getaddrinfo(node, /* service = */ NULL,
139 &ai_hints, &ai_list);
142 logger(LOG_WARNING, "Error looking up %s port %s: %s",
143 node, "any", gai_strerror(status));
146 assert(ai_list != NULL);
149 for(ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next) {
150 status = bind(c->socket,
151 ai_list->ai_addr, ai_list->ai_addrlen);
158 logger(LOG_ERR, "Can't bind to %s/tcp: %s", node, sockstrerror(sockerrno));
159 } else ifdebug(CONNECTIONS) {
160 logger(LOG_DEBUG, "Successfully bound outgoing "
161 "TCP socket to %s", node);
165 freeaddrinfo(ai_list);
167 return status ? false : true;
170 int setup_listen_socket(const sockaddr_t *sa) {
176 nfd = socket(sa->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
179 ifdebug(STATUS) logger(LOG_ERR, "Creating metasocket failed: %s", sockstrerror(sockerrno));
184 fcntl(nfd, F_SETFD, FD_CLOEXEC);
187 /* Optimize TCP settings */
190 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
192 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
193 if(sa->sa.sa_family == AF_INET6)
194 setsockopt(nfd, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
198 (lookup_config(config_tree, "BindToInterface"), &iface)) {
199 #if defined(SOL_SOCKET) && defined(SO_BINDTODEVICE)
202 memset(&ifr, 0, sizeof(ifr));
203 strncpy(ifr.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
205 if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr))) {
207 logger(LOG_ERR, "Can't bind to interface %s: %s", iface,
208 strerror(sockerrno));
212 logger(LOG_WARNING, "%s not supported on this platform", "BindToInterface");
216 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
218 addrstr = sockaddr2hostname(sa);
219 logger(LOG_ERR, "Can't bind to %s/tcp: %s", addrstr, sockstrerror(sockerrno));
226 logger(LOG_ERR, "System call `%s' failed: %s", "listen", sockstrerror(sockerrno));
233 int setup_vpn_in_socket(const sockaddr_t *sa) {
238 nfd = socket(sa->sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
241 logger(LOG_ERR, "Creating UDP socket failed: %s", sockstrerror(sockerrno));
246 fcntl(nfd, F_SETFD, FD_CLOEXEC);
251 int flags = fcntl(nfd, F_GETFL);
253 if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) {
255 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl",
262 unsigned long arg = 1;
263 if(ioctlsocket(nfd, FIONBIO, &arg) != 0) {
265 logger(LOG_ERR, "Call to `%s' failed: %s", "ioctlsocket", sockstrerror(sockerrno));
272 setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, (void *)&option, sizeof(option));
274 if(udp_rcvbuf && setsockopt(nfd, SOL_SOCKET, SO_RCVBUF, (void *)&udp_rcvbuf, sizeof(udp_rcvbuf)))
275 logger(LOG_WARNING, "Can't set UDP SO_RCVBUF to %i: %s", udp_rcvbuf, strerror(errno));
277 if(udp_sndbuf && setsockopt(nfd, SOL_SOCKET, SO_SNDBUF, (void *)&udp_sndbuf, sizeof(udp_sndbuf)))
278 logger(LOG_WARNING, "Can't set UDP SO_SNDBUF to %i: %s", udp_sndbuf, strerror(errno));
280 #if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
281 if(sa->sa.sa_family == AF_INET6)
282 setsockopt(nfd, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
285 #if defined(IP_DONTFRAG) && !defined(IP_DONTFRAGMENT)
286 #define IP_DONTFRAGMENT IP_DONTFRAG
289 #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DO)
290 if(myself->options & OPTION_PMTU_DISCOVERY) {
291 option = IP_PMTUDISC_DO;
292 setsockopt(nfd, SOL_IP, IP_MTU_DISCOVER, (void *)&option, sizeof(option));
294 #elif defined(IPPROTO_IP) && defined(IP_DONTFRAGMENT)
295 if(myself->options & OPTION_PMTU_DISCOVERY) {
297 setsockopt(nfd, IPPROTO_IP, IP_DONTFRAGMENT, (void *)&option, sizeof(option));
300 #warning No way to disable IPv4 fragmentation
303 #if defined(SOL_IPV6) && defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DO)
304 if(myself->options & OPTION_PMTU_DISCOVERY) {
305 option = IPV6_PMTUDISC_DO;
306 setsockopt(nfd, SOL_IPV6, IPV6_MTU_DISCOVER, (void *)&option, sizeof(option));
308 #elif defined(IPPROTO_IPV6) && defined(IPV6_DONTFRAG)
309 if(myself->options & OPTION_PMTU_DISCOVERY) {
311 setsockopt(nfd, IPPROTO_IPV6, IPV6_DONTFRAG, (void *)&option, sizeof(option));
314 #warning No way to disable IPv6 fragmentation
317 if (!bind_to_interface(nfd)) {
322 if(bind(nfd, &sa->sa, SALEN(sa->sa))) {
324 addrstr = sockaddr2hostname(sa);
325 logger(LOG_ERR, "Can't bind to %s/udp: %s", addrstr, sockstrerror(sockerrno));
331 } /* int setup_vpn_in_socket */
333 void retry_outgoing(outgoing_t *outgoing) {
334 outgoing->timeout += 5;
336 if(outgoing->timeout > maxtimeout)
337 outgoing->timeout = maxtimeout;
340 event_del(outgoing->event);
341 outgoing->event = new_event();
342 outgoing->event->handler = (event_handler_t) setup_outgoing_connection;
343 outgoing->event->time = now + outgoing->timeout;
344 outgoing->event->data = outgoing;
345 event_add(outgoing->event);
347 ifdebug(CONNECTIONS) logger(LOG_NOTICE,
348 "Trying to re-establish outgoing connection in %d seconds",
352 void finish_connecting(connection_t *c) {
353 ifdebug(CONNECTIONS) logger(LOG_INFO, "Connected to %s (%s)", c->name, c->hostname);
357 c->last_ping_time = now;
362 void do_outgoing_connection(connection_t *c) {
363 char *address, *port, *space;
367 logger(LOG_ERR, "do_outgoing_connection() for %s called without c->outgoing", c->name);
372 if(!c->outgoing->ai) {
373 if(!c->outgoing->cfg) {
374 ifdebug(CONNECTIONS) logger(LOG_ERR, "Could not set up a meta connection to %s",
376 c->status.remove = true;
377 retry_outgoing(c->outgoing);
382 get_config_string(c->outgoing->cfg, &address);
384 space = strchr(address, ' ');
386 port = xstrdup(space + 1);
389 if(!get_config_string(lookup_config(c->config_tree, "Port"), &port))
390 port = xstrdup("655");
393 c->outgoing->ai = str2addrinfo(address, port, SOCK_STREAM);
397 c->outgoing->aip = c->outgoing->ai;
398 c->outgoing->cfg = lookup_config_next(c->config_tree, c->outgoing->cfg);
401 if(!c->outgoing->aip) {
403 freeaddrinfo(c->outgoing->ai);
404 c->outgoing->ai = NULL;
408 memcpy(&c->address, c->outgoing->aip->ai_addr, c->outgoing->aip->ai_addrlen);
409 c->outgoing->aip = c->outgoing->aip->ai_next;
414 c->hostname = sockaddr2hostname(&c->address);
416 ifdebug(CONNECTIONS) logger(LOG_INFO, "Trying to connect to %s (%s)", c->name,
419 c->socket = socket(c->address.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
422 fcntl(c->socket, F_SETFD, FD_CLOEXEC);
425 if(c->socket == -1) {
426 ifdebug(CONNECTIONS) logger(LOG_ERR, "Creating socket for %s failed: %s", c->hostname, sockstrerror(sockerrno));
430 #if defined(SOL_IPV6) && defined(IPV6_V6ONLY)
432 if(c->address.sa.sa_family == AF_INET6)
433 setsockopt(c->socket, SOL_IPV6, IPV6_V6ONLY, (void *)&option, sizeof option);
436 bind_to_interface(c->socket);
439 /* Optimize TCP settings */
445 result = connect(c->socket, &c->address.sa, SALEN(c->address.sa));
448 if(sockinprogress(sockerrno)) {
449 c->status.connecting = true;
453 closesocket(c->socket);
455 ifdebug(CONNECTIONS) logger(LOG_ERR, "%s: %s", c->hostname, sockstrerror(sockerrno));
460 finish_connecting(c);
465 void setup_outgoing_connection(outgoing_t *outgoing) {
469 outgoing->event = NULL;
471 n = lookup_node(outgoing->name);
475 ifdebug(CONNECTIONS) logger(LOG_INFO, "Already connected to %s", outgoing->name);
477 n->connection->outgoing = outgoing;
481 c = new_connection();
482 c->name = xstrdup(outgoing->name);
483 c->outcipher = myself->connection->outcipher;
484 c->outdigest = myself->connection->outdigest;
485 c->outmaclength = myself->connection->outmaclength;
486 c->outcompression = myself->connection->outcompression;
488 init_configuration(&c->config_tree);
489 read_connection_config(c);
491 outgoing->cfg = lookup_config(c->config_tree, "Address");
494 logger(LOG_ERR, "No address specified for %s", c->name);
499 c->outgoing = outgoing;
500 c->last_ping_time = now;
504 do_outgoing_connection(c);
508 accept a new tcp connect and create a
511 bool handle_new_meta_connection(int sock) {
515 socklen_t len = sizeof(sa);
517 fd = accept(sock, &sa.sa, &len);
520 logger(LOG_ERR, "Accepting a new connection failed: %s", sockstrerror(sockerrno));
526 c = new_connection();
527 c->name = xstrdup("<unknown>");
528 c->outcipher = myself->connection->outcipher;
529 c->outdigest = myself->connection->outdigest;
530 c->outmaclength = myself->connection->outmaclength;
531 c->outcompression = myself->connection->outcompression;
534 c->hostname = sockaddr2hostname(&sa);
536 c->last_ping_time = now;
538 ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection from %s", c->hostname);
544 c->allow_request = ID;
550 static void free_outgoing(outgoing_t *outgoing) {
552 freeaddrinfo(outgoing->ai);
555 free(outgoing->name);
560 void try_outgoing_connections(void) {
561 static config_t *cfg = NULL;
563 outgoing_t *outgoing;
565 outgoing_list = list_alloc((list_action_t)free_outgoing);
567 for(cfg = lookup_config(config_tree, "ConnectTo"); cfg; cfg = lookup_config_next(config_tree, cfg)) {
568 get_config_string(cfg, &name);
570 if(!check_id(name)) {
572 "Invalid name for outgoing connection in %s line %d",
573 cfg->file, cfg->line);
578 outgoing = xmalloc_and_zero(sizeof(*outgoing));
579 outgoing->name = name;
580 list_insert_tail(outgoing_list, outgoing);
581 setup_outgoing_connection(outgoing);